开篇首先推荐一款REST接口调试的利器，Chrome的扩展程序Advanced REST client，功能十分齐全！使用它来模拟访问接口可以获取到详尽的信息，借助它排查接口是否可用。
问题1：curl访问API成功，但是使用python的urllib2模块访问却返回400。
接口规则如下：
POST /v2.0/tokens HTTP/1.0
Host: 192.168.85.183:35357
Content-Type: application/json
Accept: application/json
{
"auth":{
"passwordCredentials":{
"username":"alan",
"password":"admin"
},
"tenantName":"swifttenant1"
}
}
cURL模拟访问实现如下：
curl -s -d '{"auth":{"passwordCredentials":{"username":"alan","password":"admin"},"tenantName":"swifttenant1"}}' -H "Content-type: application/json" http://192.168.85.183:35357/v2.0/tokens | python -mjson.tool2013-09-03 05:34:20.133 23199 INFO access [-] 192.168.85.183 - - [03/Sep/2013:12:34:20 +0000] "POST http://192.168.85.183:35357/v2.0/tokens HTTP/1.0" 200 2711 python使用urllib2模块：
#!/usr/bin/python
import urllib
import urllib2
def curl_keystone_failed():
url = 'http://192.168.85.183:35357/v2.0/tokens'
values = {"auth":{"passwordCredentials":{"username":"alan","password":"admin"},"tenantName":"swifttenant1"}}
# 这里千万不要仿照网上的方法进行加密，因为它本身就没有加密的一个过程！不然还是会返回400的！
# params = urllib.urlencode(values)
params = str(values)
headers = {"Content-type":"application/json","Accept": "application/json"}
req = urllib2.Request(url, params, headers)
response = urllib2.urlopen(req)
print response.read()
if __name__ == "__main__":
curl_keystone_failed()2013-09-03 05:43:11.928 23199 INFO access [-] 192.168.85.185 - - [03/Sep/2013:12:43:11 +0000] "POST http://192.168.85.183:35357/v2.0/tokens HTTP/1.0" 400 244
随后使用httplib重写方法，查看返回的报错信息可发现，它没有获取到一个有效json格式的内容，原来python传输的时候是严格判定内容的type的。使用json来dumps一下可以解决问题！
def curl_keystone():
url = 'http://192.168.85.183:35357/v2.0/tokens'
values = {"auth":{"passwordCredentials":{"username":"alan","password":"admin"},"tenantName":"swifttenant1"}}
params = json.dumps(values)
headers = {"Content-type":"application/json","Accept": "application/json"}
req = urllib2.Request(url, params, headers)
response = urllib2.urlopen(req)
print response.read() 后台日志：
2013-09-03 05:50:52.884 23199 INFO access [-] 192.168.85.185 - - [03/Sep/2013:12:50:52 +0000] "POST http://192.168.85.183:35357/v2.0/tokens HTTP/1.0" 200 2711
